Gomphocarpus fruticosus (syn. Asclepias fruticosa) is a species of milkweed native to South Africa.<ref>Clive Bromilow; Problem Plants of South Africa, Briza Publications 2001 Template:ISBN</ref> It is also common in New Zealand where it is the main host of the monarch butterfly.Template:Citation needed The plant's tissues contain sufficient cardenolides that consumption of significant quantities of the plant's leaves, stems, or fruit may lead to death in livestock and humans.<ref>Van Wyk, Van Oudshoorn & Gerike: Medicinal plants of South Africa, Briza Publications 1997. Template:ISBN</ref><ref name="PHQ2012">Template:Cite web</ref><ref name="Wagstaff 2008">p. 36 in Template:Cite book</ref>
The species is closely related to Gomphocarpus physocarpus.